
class MyValue {
    public int val;

}

public class Test {
    public static void swap(MyValue myV1,MyValue myV2) {
        int tmp = myV1.val;
        myV1.val = myV2.val;
        myV2.val = tmp;
    }

    public static void main(String[] args) {
        MyValue myValue1 = new MyValue();
        myValue1.val = 10;

        MyValue myValue2 = new MyValue();
        myValue2.val = 20;
        swap(myValue1,myValue2);

        System.out.println(myValue1.val);
        System.out.println(myValue2.val);

    }
}
